Designing devices that can operate in remote environments on battery power is often challenging, especially if the devices need to last a long time between charges or battery swaps. Thankfully there are some things available that make these tasks a little easier, such as e-ink or e-paper displays which only use power when making changes to the display. That doesn’t solve all of the challenges of low-power devices, but [Albertas] shows us a few other tricks with this development board.
The platform is designed around an e-paper display and is meant to be used in places where something like sensor data needs to not only be collected, but also displayed. It also uses the ESP32C3 microcontroller as a platform which is well-known for its low power capabilities, and additionally has an on-board temperature and humidity sensor. With Bluetooth included as well, the tiny device can connect to plenty of wireless networks while consuming a remarkably low 34 µA in standby.
With a platform like this that can use extremely low power when not taking measurements, a battery charge can last a surprisingly long time. And, since it is based on common components, adding even a slightly larger battery would not be too difficult and could greatly extend this capability as well. But, we have seen similar builds running on nothing more than a coin cell, so doing so might only be necessary in the most extreme of situations.
“It also uses the ESP32C3 microcontroller as a platform which is well-known for its low power capabilities, and additionally has an on-board temperature and humidity sensor.”
The ESP32-C3 does not have the ability to measure temperature and humidity by itself; it can measure the internal temperature of its own single-core 32-bit RISC-V CPU though. This “Paper WiFi” device can measure temperature and humidity via a separate on-board Sensirion SHT40-1B-R2 I2C sensor.[1]
1. Sensirion AG SHT40-AD1B-R2 I2C 16-bit Temperature/Humidity Sensor, Qty.-1 $2.90 USD
https://www.digikey.com/en/products/detail/sensirion-ag/SHT40-AD1B-R2/13532084
From the project’s page:
“The devboard also includes an onboard relative humidity sensor, allowing it to measure the humidity and temperature of the surrounding environment.”
“On-board” meaning on the development board, as opposed to “on-chip”.
Those modules work for 10 years minimum while constantly measure water level and occasional report to the mothership:
https://www.ebay.com/itm/314402252807
based on STM however not ESP.
“catnip electronics” – I like that. :-)
ok, how create mesh network without normal internet?
this dev will be node